How Long Does a Female Dog Stay in Heat?

dog heat

If you have a female dog or you are thinking about getting one, it is important that you know how long they are in heat.

This information will help you with taking proper care of your dog over the long term.

When it Starts

A female dog can start going into heat when it reaches six months old. There are, however, larger breeds that don’t start going into heat until they are a year or two old. Most breeders will advise against breeding with a female dog before its third cycle. This can cause all sorts of complications that can cause a variety of issues.

How Long do Female Dogs Stay in Heat?

The average female’s heat cycle lasts anywhere from two weeks to a full month. It is fairly common for female dogs to not show any interest in mating with females for the first few days of their cycle.

The dog’s vulva swells for the duration of its cycle and goes back to its normal size when it is over. This is by far the easiest way to tell when your female dog is no longer in heat.

Most females are at their most fertile within 9-10 days after their heat cycle begins. It is possible for these dogs to become pregnant at any point while in heat. You will want to keep this in mind if you plan on breeding.

  My Dog Keeps Retching But Not Being Sick - What to Do?

Regular Cycles

Some female dogs do not go into heat regularly until a little over a year after estrus starts. Once your dog starts going into heat regularly, it should happen every six months or so. Some smaller breeds go into heat every few months. Conversely, very big dogs like Great Danes sometimes go into heat just once each year. Females keep having their heat cycles for their entire life, so there is no menopause stage like there is for humans.

female dog in heat

Phases of the Estrus Cycle

There are four different phases of a female dog’s estrus cycle that you should be aware of if you plan on breeding. This information can also be helpful when it comes to just taking care of a female dog.

  • Proestrus: This phase lasts between a week and twelve days. You will notice your dog’s vulva swelling, and sometimes there is even some bloody discharge. While a female dog can technically become pregnant during this time, it is not ideal for breeding/mating.
  • Estrus: The estrus period of a female’s heat cycle will last anywhere from a week to nine days. This is when the dog is most fertile and receptive to mates. Their vulva has become significantly enlarged as well.
  • Diestrus: During this period, your dog’s vaginal discharge will no long occur. They will not be receptive to mates. Pregnant dogs have a diestrus period that lasts up to 65 days. Dogs that are not pregnant can be in this stage for up to 90 days.
  • Anestrus: This is the final stage of a dog’s estrus cycle. During this period, your dog’s reproductive tract is essentially taking a break. Their behavior and appearance will go back to normal.
  My Dog Ate a Gum - What Should I Do?

Common Signs that a Dog is in Heat

You’ll be able to tell if your female dog is in heat by simply looking for the signs. The appearance and behavior of your dog will change when estrus begins.

Some of the most common signs of a dog in heat include:

  • Swollen vulva
  • Vaginal discharge (blood)
  • Increased alertness
  • Displaying her hindquarters to male dogs

Caring for Your In-Heat Dog

There are some things that you will need to consider when your dog is in heat. This will make it a lot easier to care for it during this delicate period of time.

Separate it from the Males

If you aren’t trying to breed, it is important that you keep your in-heat female away from any males that haven’t been neutered. This is just asking for trouble, so you’ll need to keep it in mind. You also want to keep her on a leash whenever you take her outside of your home. The last thing you want is for her to run up to any eager males.


Some people crate their female dogs while they are in heat for short periods. This helps with minimizing the mess that can come with bloody vaginal discharge during the heat cycle. If you don’t want to crate your dog, you can simply close off certain parts of your house. There is also the option of putting a diaper on them until the discharge is no longer an issue.

Give Her Some Extra Attention

Female dogs that are in heat can become very anxious and stressed, so you’ll want to give yours some extra attention. This will help her a lot when it comes to getting through a somewhat difficult period. You can also give her some delicious treats sometimes, but don’t overdo it. If you want to avoid this issue entirely, you can always have your dog spayed. There are many benefits of this to consider before making a final decision either way.

  My Dog’s Eyes Rolls Back in its Head - Common Reasons


  • Some female dogs start going into heat when they are six months old, while others start when they reach two years of age.
  • Smaller dogs tend to go into heat more frequently than larger ones.
  • Females reach their peak fertility within 9 to 10 days of starting their heat cycle.
  • It could take up to a year for your dog to start going into heat regularly.
  • Most dogs go through an estrus cycle every six months, while others experience this every 3-4 months.
  • Some of the common signs of a dog in heat include a swollen vulva, increased alertness, and displaying their hindquarters to males.
  • If you want to avoid having a pregnant female dog, keep it away from unneutered males while it is in heat.
  • In order to minimize the mess associated with your dog’s bloody discharge, you can put diapers on it.
  • You might also want to crate your dog for short periods to avoid messes.
Was this article helpful?